An observer cannot see the coin in an empty glass as shown in Diagram (a). However, he can see the coin when the glass is filled with water as shown in Diagram (b).

Diagram (a) Diagram (b) The observer can see the coin in Diagram (b) due to A. the total internal reflection of light B. the refraction of light C. the reflection of light D. the diffraction of light 3. The critical angle in glass is 42o. What is the refractive index of the glass? A. 1.2 B. 1.3 C. 1.4 D. 1.5 E. 1.6

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4.

The diagram shows a ray of light from a small bulb striking on a plane mirror.

Where is the image of the bulb formed and its characteristic? A At P and virtual B At Q and real C At R and virtual 5. The table below shows the characteristics of the images formed by a concave mirror for various positions of the object. All symbols used have the usual meanings. Which of them is not true? Position of object Characteristics of image A u > 2f Diminished, inverted, real B f < u < 2f Magnified, inverted, real C u=f Same size, inverted, real D u<f Maginfied, upright, virtual

6. Which of the following ray diagram is correct?

A 50o 50o C

B

C

F

C

F

Plane mirror

Convex mirror

Concave mirror

7. The depth of a swimming pool appears to be less than its actual depth. The light phenomenon which causes this is A. Reflection B. Refraction C. Diffraction D. Interference 8. Which of the following is the characteristics of an image formed by a magnifying glass? A. Magnified, virtual, inverted B. Diminished, real, upright C. Magnified, virtual, upright D. Diminished, virtual, inverted 9. In the following ray diagram, the image formed on the screen is not clear (not sharp).

Lens
Object

Screen

2

A. B. C. D.

Which of the following changes will produce a sharp image on the screen? Replace the lens with another convex lens of longer focal length. Replace the lens with another concave lens of shorter focal length. Move the object further from the lens. Move the screen further from the lens.

10. Diagram 13 shows the arrangement of apparatus for an experiment to investigate the relationship between object distance and image distance. Screen To power supply Convex lens Object Sharp image

Light box

Metre rule 20.0 cm 50.0 cm When the lens is placed at 20.0 cm from the object, the screen needed to be adjusted at 50.0 cm to project a sharp image on the screen. The focal length of the lens is A 10.0 cm B 12.0 cm C 14.3 cm D 15.6 cm ANSWERS FOR SECTION A NO 1 2 3 4 5 SECTION B ANSWER NO 6 7 8 9 10 ANSWER

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1. sky
Layer of cold air

eye X

Layer of Warm air

Image of the sky Road
The diagram shows how mirages are formed on a hot day. (a) Compare the density of warm air and cold air. …………………………………………………………………………………….. [1 m] Explain what happened at point X when the ray of light hit the layer of warm air? …………………………………………………………………………………….. …………………………………………………………………………………….. [2 m] Name the phenomenon involved.

(b)

(c)

2.

…………………………………………………………………………………….. [1 m] A student is given two convex lenses P and Q.The power of lens P is 10 D and lens Q is 2 D. He wishes to construct a powerful astronomical telescope. (a) What is meant by power of lenses? (b) ………………………………………………………………………………..[1m] Calculate the focal length of lens P and Q

[3m] (c) State the lens that will be used as the objective lens. ………………………………………………………………………………..[1m]

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(d)

Determine the distance between lens P and Q if the arrangement of the telescope is at normal adjustment? ………………………………………………………………………………..[1m] Calculate the magnification of the final image formed by the telescope at normal adjustment. [2m]

(e)

3.

Eye

air water

Figure above shows the eye of a person looking at a fish. a) Sketch a ray originating from the eye of the fish to show why the image of the fish is seen closer to the surface. [2m] b) The fish is at a depth of 2 m. If the refractive index of water is 1.33, calculate the apparent depth of the fish. [2m] 4. Figure shows a candle is placed 50 cm from a concave mirror which focal length is 20 cm. [Diagram is drawn to scale 1 cm : 10 cm]

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Concave mirror candle

8 cm

6 cm

4 cm

2 cm

(a)(i) (ii)

Draw a ray diagram on the figure above to show how the image of the candle is formed. [2m] And hence, state two charecteristics of the image formed in the ray diagram that you have drawn.

………………………………………………………………………………[2m] (b) (i) Indicate and label Q on the Figure above to show the position of the candle which will produce a virtual, upright and magnified image. [1m] (ii) Suggest one application of the concave mirror in situation (b) (i). ………………………………………………………………………………[1m]